The drive-thru window is ubiquitous among fast food restaurants. One frequent problem with this system is the customer receiving an incorrect order. If the customer drives off before fully checking the order, it is frustrating and time-consuming to return and have it corrected. If the customer stays at the drive-thru window long enough to completely check all received items, everyone else in line must wait, significantly reducing overall throughput. Frequent errors in received items can result in lost customers.
Much has been done to optimize the drive-thru system, and in particular to improve accuracy. Many restaurants now include an outdoor display to show the order as entered by the cashier—this way the customer can verify that the order was entered correctly. This does help reduce one error mechanism—incorrect order entry—but doesn't help if the cashier bags the order incorrectly, or if items were wrapped incorrectly. Some restaurants have automatic drink machines. These fully automatic machines handle all drinks associated with an order, reducing the chance of error, but only for drinks. Drive-thru systems have been rearranged to include two windows—a cashier at one window, and a food delivery person at a second window. This improves throughput, and also reduces errors by reducing the number of disparate tasks each worker must perform. The cashier function is even being outsourced to off-site locations, where orders may be received without distractions from the restaurant operations. This results in improved order-taking accuracy, but still does not fully address mistakes in bagging the order and delivering it to the customer.
Another problem with incorrectly assembled and delivered drive-thru orders is the lack of accountability. With the current system, if a customer returns due to an incorrect order, there is no mechanism to track what the error was, or who was responsible.